This virtual meter can help you monitor the usage of your RAM and CPU and run tests to determine LAN bandwidth, WiFi signal strength, hard drive memory and activity and battery charge. Whenever your computer slows down, this tool can display the problem and provide you with detailed information. It gives a graphical representation of your connection speed and bandwidth behavior.
The app has a very simple and intuitive interface that lets you choose from as many 73 backgrounds and 19 skins. It can be downloaded from here.